Froth pump

ABSTRACT

CENTRIFUGAL PUMPS HAVING AN IMPELLER AT THE LOWER END OF A VERTICAL SPINDLE, A CASING SURROUNDING THE IMPELLER, AN INTAKE OPENING THROUGH THE UPPER WALL OF THE CASING AND A FEED CHAMBER SURROUNDING THE SPINDLE AND COMMUNICATING WITH THE INTAKE OPENING ARE MODIFIED, IN ORDER TO HANDLE FROTHY FLUIDS BY VANING THE PERIPHERY OF THE OPENING IN THE CASING SO THAT PART OF THE FEED IS RETURNED TO THE FEED CHAMBER WITH INCREASED ENERGY CAUSING A SHEARING VORTEX MOTION IN THE FEED CHAMBER.

June 20, 1972 c. H. WARMAN FROTH PUMP Filed May 15, 1970 a 0 0 00 00 \r 0 O0. 0 0 4 2 o u o 0 0 000 0 0 0 0 0 o 000 000 w n n 0 0 O o u 0 0000\ .00 00a 5|. 0 a o o o 0 0 0 3 0 0 6 cum: 5 H WARMW INVENTOR 1 Mada, 24M

United States Patent 3,671,135 FROTH PUMP Charles Harold Warman, Castlecrag, New South Wales,

Australia, assignor to Warman Equipment (International) Ltd., Belmont, Western Australia, Australia Filed May 15, 1970, Ser. No. 37,583

Int. Cl. F04d I /00, 9/00; B01d 47/00 US. Cl. 41553 7 Claims ABSTRACT OF THE DISCLOSURE Centrifugal pumps having an impeller at the lower end of a vertical spindle, a casing surrounding the impeller, an intake opening through the upper wall of the casing and a feed chamber surrounding the spindle and communicating with the intake opening are modified, in order to handle frothy fluids by vaning the periphery of the opening in the casing so that part of the feed is returned to the feed chamber with increased energy causing a shearing vortex motion in the feed chamber.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION In a pump according to the invention part of the feed passing from the feed chamber into the pump casing through the intake opening is returned to the feed chamber with increased energy through a vaned peripheral portion of said intake opening and serves to cause in the feed chamber a shearing vortex motion which is very effective in disengaging air entrained in the frothy portion of the feed. The vane or vanes provided in the intake opening may eflectively take a variety of forms but a preferred form which returns fluid to the feed chamber with maximum conservation of energy comprises multiple spiral vanes projecting inwardly from the outer wall of the intake opening and leaving a clear annular space between the inner ends of the vanes and the spindle for entry of feed to the pump, the handing of said spiral vanes being such that fluid rotating within the casing about the vertical axis of the pump in the direction of rotation of the pump impeller may enter between the vanes and return to the feed chamber without alteration in direction of rotation. The proportion of the feed so returned from the pump to the feed chamber may be predetermined by the extent to which the vaned portion occupies the annulus between the spindle and the outer wall of the feed opening and also by the spiral angle and thickness of the vanes.

A variety of shapes of feed chamber may be used but a 'form found to be efiective in disentraining air and conserving the energy of the fluid returned from the pump is a frustum of an upwardly divergent cone symmetrical about the pump spindle having its lower end joined to the intake opening of the pump and its upper end joined to a cylindrical section the vertical dimension of which may vary according to the circumstances of patricular usage but is typically approximately half of the vertical dimension of the conical frustum. The included angle of the 3,671,135 Patented June 20, 1972 conical frustum may also vary considerably depending on the requirements of any given application but typically approximates 55 While the feed to the intake chamber may be introduced in a number of ways a preferred method is by means of a pipe downwardly sloping at an angle of about 15 and tangentially joining the cylindrical portion of the feed chamber in such manner that the feed fluid in passing into the feed chamber flows on the wall of the chamber with the same direction of rotation about the pump axis as that of the pump impeller.

In some applications of the invention it may be necessary to limit the height of the vortexing fluid in the feed chamber and for this purpose one or more spiral vanes inwardly projecting from the cylindrical portion of the feed chamber may be provided having a handling such that fluid vortexing in the feed chamber and entering the vane or vanes near the top of the cylindrical portion is deflected downwardly without change in the direction of its rotation about the pump axis.

DESCRIPTION OF THE DRAWING A specific form of the invention'is illustrated in the accompanying drawings wherein:

FIG. 1 is an axial section of a pump adapted to function according to the invention.

FIG. 2 is a part plan view on the line AA of FIG. 1.

Like parts are illustrated by like characters throughout the specification and drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in the drawings 1 is an impeller enveloped in a casing 3 and mounted on the lower end of a vertical spindle 2 supported and rotated clockwise as viewed in plan by any suitable means not shown in the drawings, said vertical spindle passing through a cylindrical intake opening 4 in the upper wall 5 of the casing 3. A feed chamber 6 surrounding vertical spindle 2 comprises the frustum of an upwardly divergent cone 7 connected at its lower end to the intake opening 4 and at its upper end to a cylindrical section 8.

Feed enters the pump tangentially through downwardly sloping feed pipe 9 joined tangentially to the upper cylindrical portion 8 of the feed chamber 6, flows downwardly in clockwise vortex motion through the feed chamber to the intake opening 4 and passes into the pump casing 3 through the clear annular space between the inner ends of three left hand spiral vanes 10 and the spindle 2. Portion of the fluid energised within the casing 3 by the rotation of the impeller 1 enters the spaces between the vanes 10 and returns upwardly in clockwise spiral motion to the outside of the conical section 7 of the feed chamber 6 where it engages the feed as at interface 11 in a shearing vortex motion found to be effective in disengaging air entrained in the feed.

To limit the height of the vortexing fluid in the feed chamber six right hand spirally shaped vanes 12 are provided inwardly projecting from the cylindrical portion 8 of the feed chamber and serve to deflect downwardly, without change in its direction of rotation about the pump axis, fluid which might otherwise overflow the feed chamber.

What I claim is:

1. A froth pump, comprising, a rotatable vertical spindle, an impeller at the lower end of said rotatable vertical spindle, a casing enveloping said impeller, an opening through the upper wall of said casing about said spindle, a feed chamber surrounding said spindle and downwardly communicating with said opening in said casing and adapted to receive the pump feed, a cylindrical section, said feed chamber being symmetrical about said spindle and in the form of an upwardly diverging frustum of a cone joined at its upper end to said cylindrical section, said feed chamber containing said pump feed in vortex motion and transforming it to and through said opening into said casing, and vanes projecting inwardly from the periphery of said opening in said casing towards said spindle and adapted to return to said feed chamber portion of the fluid energised within said casing by said impeller.

2. A froth pump according to claim 1 wherein each said vane is of spiral form and the handing of said spiral is such that said fluid is returned to said feed chamber without change in direction of its rotation about the axis of said pump.

3. A froth pump according to claim 1 wherein a feed pipe joins said cylindrical section of said feed chamber substantially tangentially and discharges thereinto in the direction of rotation of the vortex flow therein.

4. A froth pump according to claim 1 wherein said feed chamber is provided with vanes projecting inwardly from the wall of the cylindrical portion thereof and downwardly sloping in the direction of the vortex flow of the feed therein.

5. A froth pump according to claim 1 wherein each vane is of spiral form and the handing of the spiral is such that fluid is returned to the feed chamber without change in direction of its rotation about the axis of said pump and wherein said feed chamber is symmetrical about said spin- 4 dle and is in the form of an upwardly diverging frustum of a cone joined at its upper end to said cylindrical section.

6. A froth pump according to claim 5, wherein a feed pipe joins said cylindrical section of said feed chamber substantially tangentially and discharges thereinto in the direction of rotation of the vortex flow therein.

7. A froth pump according to claim 5 wherein said feed chamber is provided with vanes projecting inwardly from the wall of said cylindrical section thereof and downwardly sloping in the direction of the vortex flow of the feed therein.

References Cited UNITED STATES PATENTS 1,697,202 1/1929 Nagle 4l5185 1,281,478 10/1918 Antisell 415-1 83 1,891,201 12/1932 Hoff 415-175 FOREIGN PATENTS 954,392 4/1964 Great Britain 4l5-121 284,608 3/1964 Netherland 415-121 HENRY F. RADUAZO; Primary Examiner US. Cl. X.R.

r 41s 1s3, 204; 55-203 

